1. Field of the Invention
The present invention relates to a mechanism for attaching and detaching a disk cartridge in a disk drive unit.
2. Description of the Related Art
In a general mechanism for attaching and detaching a disk cartridge, cam portions for moving the disk cartridge therealong have a constant inclination angle such as 45.degree.. In the case of ODD, the attractive force of a magnet for chucking a disk to a spindle is small. For example, the magnet can bear about 600 g in weight. Accordingly, force for ejecting the cartridge from the magnet is not strong so much even when the inclination angle of the cam portions is a large value such as 45.degree.. For example, a weight about 2 Kg can be ejected by the ejecting force in this case. In contrast to this, in the case of HDD, the attractive force of a magnet is large. For example, the magnet can bear about 1400 g in weight. Accordingly, the ejecting force is strong in such a state so that operability is greatly reduced.
In the case of ODD, when the cartridge is pressed against a guide pin at the loading time of the cartridge, a load applied to the cartridge is composed of only the empty weight of the cartridge. Accordingly, there are no disadvantages that the cartridge is floated from the guide pin in such a state. However, in the case of HDD, the attractive force of the magnet is strong and the load at the loading time of the cartridge is large in comparison with that in the case of ODD since a hub seal, etc. are disposed in the attaching/detaching mechanism. Accordingly, in the case of HDD, the cartridge is floated from the guide pin.